The present invention relates to a method in displacement of objects, for example in displacement of an object from a resting position to a working position or vice verse, and in which method a device is arranged comprising a screw with at least two threads of different pitches and which screw is arranged in engagement with a body or with one or more internal and with the screw matching threads shown by the body. At this the screw is arranged to a first object and the body to a second object. In the method the first object and/or the second object is brought to displace a distance when the screw and body are in engagement with one another in a first thread or for example a coarse thread and also subsequently when the screw and body are in engagement with one another in a second thread or for example a fine thread or vice verse.
In a great number of different situations there is a need to be able to rapidly displace an object in a device or in a direction towards or from a device or a second object, for example in order to attain a quick engagement or a quick release action and removal of a device or an object or other rapid movement. Often, it exists also a need to be able to increase the tightening tension, as when clamping a device, a material, etc. In applicable cases there is also a need to be able to reduce that power, which is required to arrange an object in a working position or to remove the object from a working position, as in a manual handling, for example when an object is clamped. In certain cases there is also a need to attain a function of self-obstruction. Areas where such a need exists are for example in clamping jaws, vices, puller tools, lifting jacks, various kinds of supporting legs, sliding valves, etc.
For carrying out a method it is required a device. In known devices in question one has been forced to compromise between good tension or tightening force action and high speed of the displacement. Thus, one has got a low tension in designs with rapid displacement of objects. One has got a slower displacement of objects in designs with improved tension. With regard to this it would be advantageous if one was able to make a rapid displacement of objects when none or low tension or tightening force action is needed and in cases when tension or high tension is needed be able to have the device to work with high tension.
In for example a supporting stand with a land wheel for a trailer, the stand is arranged releaseable from a folding position and shows a screw with a thread with a small pitch. At this the supporting stand can be dropped so that the land wheel will be situated close to a foundation, after which the vehicle or its chassis can be raised by rotating the screw. The rotation of the screw can be effected by manual power as the screw has a small pitch and the screw will also be self-obstructed. Of course, such a supporting stand can instead for being able to fold be arranged only vertically adjustable by rotation of the screw. In such a case the screw must, however, be rotated a great many revolutions to reach a working position and a resting or storing position respectively, which is i.a. time-consuming.
A previously known device which, however, has not been used in connection with supporting stands, shows a screw with two threads with different pitches and a nut, which is arranged with the screw with matching threads. By a radial turn of a part of the nut, an angular displacement of the threads is effected in said part in relation to the threads in the remaining part of the nut, whereby the nut can change from a first thread to a second thread of the screw. Such a method has, however, certain limitations, as it requires a manual handling and a turning of a part in a device in order to be able to carry out the method. The fields of application are further restricted for the method by the shaping and way of operation of the device. In addition, it has been shown difficult to carry out intended methods due to the shaping of the changing devices. The function of the screw and/or the nut has not been satisfactory. Further, the method is impossible to utilized in such occasions when the device for carrying out the method must be contained within a limited or small space.